学步园

最近工作需要，正在研究ATL/COM方面的东东。今天正好看到了集合(Collection)和枚举器(Enumerater)，这个两个东东个人觉得不是很好理解，反正我是看了好几遍书，然后又在网上找了些资料，才算勉强有些入门，然后写了几个小练习。

练习一： 使用CComEnum实现，使用的IEnumVARIANT枚举接口

1.IDL文件

import "oaidl.idl";<br /> import "ocidl.idl";</p> <p>[<br /> object,<br /> uuid(FBCAD1D2-9148-4DD4-8FAC-EB41420E27F8),<br /> dual,<br /> nonextensible,<br /> helpstring("INumbers 接口"),<br /> pointer_default(unique)<br /> ]<br /> interface INumbers : IDispatch{<br /> [propget, id(1), helpstring("属性 Count")] HRESULT Count([out, retval] LONG* pVal);<br /> [propget, id(DISPID_VALUE), helpstring("属性 Item")] HRESULT Item([in] LONG n, [out, retval] LONG* pVal);<br /> [propget, id(DISPID_NEWENUM), helpstring("属性 _NewEnum")] HRESULT _NewEnum([out, retval] IUnknown** pVal);<br /> };<br /> [<br /> uuid(03DE570D-D020-4A6C-B21F-AC92963C1D42),<br /> version(1.0),<br /> helpstring("MyNumbers 1.0 类型库")<br /> ]<br /> library MyNumbersLib<br /> {<br /> importlib("stdole2.tlb");<br /> [<br /> uuid(C3A5B58A-F764-43FF-82B9-A7CBB0D1F867),<br /> helpstring("Numbers Class")<br /> ]<br /> coclass Numbers<br /> {<br /> [default] interface INumbers;<br /> };<br /> };

2.Numbers.h实现

#pragma once<br /> #include "resource.h" // 主符号</p> <p>#include "MyNumbers.h"<br /> #include <vector></p> <p>#if defined(_WIN32_WCE) && !defined(_CE_DCOM) && !defined(_CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA)<br /> #error "Windows CE 平台(如不提供完全 DCOM 支持的 Windows Mobile 平台)上无法正确支持单线程 COM 对象。定义 _CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA 可强制 ATL 支持创建单线程 COM 对象实现并允许使用其单线程 COM 对象实现。rgs 文件中的线程模型已被设置为“Free”，原因是该模型是非 DCOM Windows CE 平台支持的唯一线程模型。"<br /> #endif</p> <p>typedef CComEnum<IEnumVARIANT,&IID_IEnumVARIANT,VARIANT,_Copy<VARIANT>> MyNumbersEnum;</p> <p>// CNumbers</p> <p>class ATL_NO_VTABLE CNumbers :<br /> public CComObjectRootEx<CComSingleThreadModel>,<br /> public CComCoClass<CNumbers, &CLSID_Numbers>,<br /> public IDispatchImpl<INumbers, &IID_INumbers, &LIBID_MyNumbersLib, /*wMajor =*/ 1, /*wMinor =*/ 0><br /> {<br /> public:<br /> CNumbers()<br /> {<br /> m_Num.push_back(10);<br /> m_Num.push_back(11);<br /> m_Num.push_back(12);<br /> m_Num.push_back(13);<br /> m_Num.push_back(14);<br /> m_Num.push_back(15);<br /> }</p> <p>DECLARE_REGISTRY_RESOURCEID(IDR_NUMBERS)</p> <p>BEGIN_COM_MAP(CNumbers)<br /> COM_INTERFACE_ENTRY(INumbers)<br /> COM_INTERFACE_ENTRY(IDispatch)<br /> END_COM_MAP()</p> <p> DECLARE_PROTECT_FINAL_CONSTRUCT()</p> <p> HRESULT FinalConstruct()<br /> {<br /> return S_OK;<br /> }</p> <p> void FinalRelease()<br /> {<br /> }</p> <p>public:</p> <p>public:<br /> STDMETHOD(get_Count)(LONG* pVal);<br /> public:<br /> STDMETHOD(get_Item)(LONG n, LONG* pVal);<br /> public:<br /> STDMETHOD(get__NewEnum)(IUnknown** pVal);<br /> protected:<br /> std::vector<long> m_Num;<br /> };</p> <p>OBJECT_ENTRY_AUTO(__uuidof(Numbers), CNumbers)

3.Numbers.cpp实现

// Numbers.cpp : CNumbers 的实现</p> <p>#include "stdafx.h"<br /> #include "Numbers.h"</p> <p>// CNumbers</p> <p>STDMETHODIMP CNumbers::get_Count(LONG* pVal)<br /> {<br /> // TODO: 在此添加实现代码</p> <p> *pVal = (long)m_Num.size();<br /> return S_OK;<br /> }</p> <p>STDMETHODIMP CNumbers::get_Item(LONG n, LONG* pVal)<br /> {<br /> // TODO: 在此添加实现代码</p> <p> long Max = (long)m_Num.size();<br /> if (n >= Max)<br /> {<br /> return E_OUTOFMEMORY;<br /> }<br /> *pVal = m_Num[n];<br /> return S_OK;<br /> }</p> <p>STDMETHODIMP CNumbers::get__NewEnum(IUnknown** pVal)<br /> {<br /> // TODO: 在此添加实现代码</p> <p> CComObject<MyNumbersEnum>* pNumbersEnum = NULL ;<br /> HRESULT hr = CComObject<MyNumbersEnum>::CreateInstance(&pNumbersEnum);<br /> if (SUCCEEDED(hr))<br /> {<br /> pNumbersEnum->AddRef();<br /> long lSize = (long)m_Num.size();<br /> VARIANT* pVARIANT = new VARIANT[lSize];<br /> if (pVARIANT)<br /> {<br /> ZeroMemory(pVARIANT,sizeof(VARIANT)*lSize);<br /> VARIANT* pTemp = pVARIANT;<br /> std::vector<long>::iterator it = m_Num.begin();<br /> for (;it != m_Num.end();it++,pTemp++)<br /> {<br /> pTemp->vt = VT_I4;<br /> pTemp->lVal = *it;<br /> }</p> <p> hr = pNumbersEnum->Init(&pVARIANT[0],&pVARIANT[lSize],0,AtlFlagTakeOwnership);<br /> if (SUCCEEDED(hr))<br /> {<br /> hr = pNumbersEnum->QueryInterface(IID_IUnknown,(void**)pVal);<br /> }<br /> else<br /> {<br /> hr = E_OUTOFMEMORY;<br /> }<br /> }<br /> pNumbersEnum->Release();<br /> }<br /> return hr;<br /> }

4.测试Client

#include <iostream><br /> #include <atlbase.h><br /> #include <atlcomcli.h><br /> #include <atlcom.h></p> <p>#include "../MyNumbers/MyNumbers.h"<br /> #include "../MyNumbers/MyNumbers_i.c"<br /> using namespace std;</p> <p>int main()<br /> {</p> <p> CoInitialize(NULL);<br /> try<br /> {<br /> CComPtr<INumbers> pNum = NULL;<br /> HRESULT hr;<br /> hr = CoCreateInstance(CLSID_Numbers,NULL,CLSCTX_INPROC,IID_INumbers,(void**)&pNum);<br /> if (FAILED(hr))<br /> {<br /> cout << "CoCrateInstance error." << endl;<br /> CoUninitialize();<br /> return -1;<br /> }</p> <p> long lSize = 0;<br /> pNum->get_Count(&lSize);<br /> cout << "Size: " << lSize << endl;</p> <p> CComPtr<IEnumVARIANT> pEnum = NULL;<br /> CComPtr<IUnknown> pUnknown = NULL;<br /> pNum->get__NewEnum(&pUnknown);<br /> pUnknown->QueryInterface(IID_IEnumVARIANT,(void**)&pEnum);</p> <p> for (int i=1;i<=lSize;i++)<br /> {<br /> VARIANT varTemp[1];<br /> ULONG lFetched = 0;<br /> hr = pEnum->Next(1,&varTemp[0],&lFetched);<br /> if (SUCCEEDED(hr))<br /> {<br /> CComVariant comvar;<br /> comvar.Attach(&varTemp[0]);<br /> wcout << "Number " << i << " is " << comvar.lVal << endl;<br /> }</p> <p> }<br /> }<br /> catch (...)<br /> {<br /> cout << "an expection occur......" << endl;<br /> }</p> <p> CoUninitialize();<br /> system("pause");<br /> return 0;<br /> }